I am trying to implement a simple demo on sel4 using camkes. I need to add some external hardware like sensors to my demo. For this purpose I need GPIO programming. Could you please point me to some example GPIO components?

Should I add hardware component? or just use <platsupport.GPIO.h> to write signal on pins on source files?

Hello Parveneh, We do not have a GPIO component, but we are currently developing one. However, almost all the hardware related components (TimeServer, SerialServer) in global-components[1] are just an interface over the particular drivers in libplatsupport[2]. So developing an GPIO component for your demo should be fairly easy as long as there are GPIO drivers for your target platform in libplatsupport[3]. You would need a hardware component if the GPIO device requires some registers and/or interrupts to be mapped in. For an example on creating a hardware component you could take a look at the CAmkES timer tutorials[4]. As I mentioned above, if there are GPIO drivers for your target platform in libplatsupport, you could use the GPIO interfaces defined in "platsupport/gpio.h". Otherwise, you would have to develop your own GPIO drivers for your target platform. I hope this answers your questions, and if you have any other questions feel free to ask them on the mailing list. Sincerely, Damon Lee PS: Sorry if you are receiving this again, I sent it out yesterday but I may have done something wrong as it did not seem to have reached the mailing list. [1] https://github.com/SEL4PROJ/global-components/tree/master/components [2] https://github.com/seL4/util_libs/tree/master/libplatsupport [3] https://github.com/seL4/util_libs/tree/master/libplatsupport/src/plat [4] https://docs.sel4.systems/Tutorials/hello-camkes-timer.html